Ok, but will it be enough in 5 years? My current MBP lasted 5 years. I'm counting on my next one to be around for 5 years as well. It's something I have to think about since I can't upgrade it to 32gb down the road.
Unless some radical shift happens then I think 16GB will be completely fine in 5 years.
My prediction: In 5 years 16GB will be fine.
Why? Because RAM requirements passed from "We need more, it'll speed things up" to "We've got enough" a while back, and there just isn't much you can do with the extra. Once you're no longer space constrained it just ceases to move the needle.
I'm not defending Apple here, but generally it's hard to think of something that would require 32GB of ram that doesn't better belong on a server. Once you get to that kind of size you'll probably want ECC or stable uptime or other features you'll get on an actual server rather than a machine you turn on and off several times a day.
It's not a question of whether 16GB is sufficient. It's a question of whether 16GB is an reasonable maximum for a "Pro" machine.
OK, forget about expansion and maybe adding 16GB RAM and a few more TB of flash in a couple years. Clearly that ship has sailed.
But 16GB RAM is the absolute minimum I would buy with a new machine today. For that to be the Pro's maximum is wrong.
16G wasn't available and was considered overkill. I remember that quite clearly because it was 2011 and I bought my fully maxed out Macbook Pro from apple with 8G of ram and I was looking at 16G upgrade kits on iFixIt a year later.
So, no, 16G was not "fine", 16G was considered future proof.
And when that happens, some developers start getting lazy and careless with how they use memory, and we return to the "we need more" part of the cycle.
I can certainly do that part of my development on some bit of dedicated hardware that sits in the office, but that means I need networking there, which means I can't code on the road etc.